Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 18-05-2008, 13:14   #16
Registered User
 
Fishspearit's Avatar

Join Date: Jan 2006
Location: FL
Posts: 576
Red face

Quote:
Experience indicates that the catamaran is more likely to sustain a lightning strike;
That's the line that has me scratching my head

Can anyone explain why that would be?
__________________

__________________
www.LionfishHunting.com
Fishspearit is offline   Reply With Quote
Old 18-05-2008, 14:09   #17
Armchair Bucketeer
 
David_Old_Jersey's Avatar

Join Date: Oct 2006
Posts: 10,013
Images: 4
No idea about electrickery - but maybe that should read "More likely to make a claim following a lightening strike"?

Do they earth differently? or just have more toys onboard to fry and claim for?....could of course just be a statistical blip accross his desk.

Or God has a Mono
__________________

__________________
David_Old_Jersey is offline   Reply With Quote
Old 18-05-2008, 14:53   #18
CF Adviser
 
TabbyCat's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: cruising in the Pacific
Boat: MaineCat Catamaran 41'
Posts: 334
Images: 1
Send a message via Skype™ to TabbyCat
I don't have any statistical data to share, just anecdotal information:

1. Most cats have lots of metal running horizontally between the hulls, such as very large cables connecting the battery banks across the hulls, metal rods between the rudders, and the crossbeam at the bow. The theory is that all this horizontally aligned metal presents a more appealing target for lightning.

2. Most cats don't have metal in their keels, so are not as well grounded as a monohull.

I have personally taken a surprising number of claims for cats, especially when hauled out ashore. I know of two recent incidents in which cats were hauled out for less than a week (one for bottom painting, another for a mechanical repair) and they were struck by lightning. We have a "strikeshield" on our cat which is a heavy cable that attaches to the bottom of the mast & hangs in the water. Next time we haul out, I'm going to make sure it is well buried in the ground.
__________________
Susan
IMIS - Int'l Marine Ins Svcs
http://www.MarineInsurance.CC
TabbyCat is offline   Reply With Quote
Old 18-05-2008, 17:16   #19
Senior Cruiser
 
Therapy's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: W Florida
Boat: The Jon boat still, plus a 2007 SeaCat.
Posts: 6,894
Images: 4
Quote:
Originally Posted by TabbyCat View Post
. We have a "strikeshield" on our cat which is a heavy cable that attaches to the bottom of the mast & hangs in the water. Next time we haul out, I'm going to make sure it is well buried in the ground.
Many years ago in Tampa Bay there was this little (uninsured) 18ft Westerly that was sailed in all sorts of weather. It had three stays and at the base of each one was clamped a cable that dragged in the water.

Don't know if it worked or not but never a strike............
__________________
Therapy is offline   Reply With Quote
Old 18-05-2008, 17:41   #20
Senior Cruiser

Cruisers Forum Supporter

Join Date: Nov 2005
Location: Tasmania
Boat: VandeStadt IOR 40' - Insatiable
Posts: 2,317
Images: 91
I don't believe that this type of action will prevent a lightning strike. I think the idea is that if you do get struck, the effect will be lessened.
__________________
Weyalan is offline   Reply With Quote
Old 18-05-2008, 18:12   #21
Senior Cruiser
 
Therapy's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: W Florida
Boat: The Jon boat still, plus a 2007 SeaCat.
Posts: 6,894
Images: 4
Quote:
Originally Posted by Weyalan View Post
I don't believe that this type of action will prevent a lightning strike. I think the idea is that if you do get struck, the effect will be lessened.
I have heard that too.

I have heard also that if all is well grounded, the "cloud" sees the boat as the same as flat seas - like it isn't there.

This has nothing to do with marinas or "flash over" from other nearby strikes.


But is off topic too.

Sorry.
__________________
Therapy is offline   Reply With Quote
Old 19-05-2008, 00:04   #22
Moderator Emeritus
 
David M's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: San Francisco Bay
Boat: research vessel
Posts: 10,150
Quote:
Originally Posted by GordMay View Post
* Notwithstanding their growing popularity, catamarans are more exposed to loss than monohulls. Experience indicates that the catamaran is more likely to sustain a lightning strike; the catamaran is more exposed to dismasting than other vessels; the beam of the catamaran makes secure mooring more difficult to obtain; catamarans present a significant capsizing risk. (Any vessel with an escape hatch in the hull bottom should be viewed with concern.); the stability of the catamaran makes it popular with those with less than extensive seagoing skills; ad infinitum
I would like to see these statistics and not just opinions. Do catamarans actually have more claims than monohulls? Are there any available statistics? This may make or break whether I buy a catamaran or not. Not so much the premiums, but are cats statistically more dangerous?

How on earth a catamaran is more prone to lightning strikes is beyond me. Any ideas?

David
__________________
David

Life begins where land ends.
David M is offline   Reply With Quote
Old 19-05-2008, 00:12   #23
Senior Cruiser
 
Alan Wheeler's Avatar

Cruisers Forum Supporter

Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
Images: 102
There are a lot of "old wives tales" out there. Most of it is rubbish. The odd one or two have merrit. But then a strike occurs that simply didn't play by the rules and it leaves scientists scratching their heads again. Some things that are known.
Lightning can travel vast distances. As much as ten miles. Those few feet from top of mast to water is nothing after traveling so far.
Lightening arresters or brushes at the top of the mast don't work.
If the electrical energy doesn't get your electrics, the electromagnetic field sure will.
The cone of protection is a bout as useless as "Controls" (maxwell smart) cone of silence.
Lightning does not always go for the highest mast.
Lightning does not always go for the best conductor.
A large conductor over the side of the boat will not completely protect you. A cable the same diameter of the mast might be better, but not really user that friendly.
If you are struck and the Electrical discharge doesn't get yo, the heat probably will. Strikes can cause a lot of explosive type damage and the heat vaporising components can literally blow panels, bulkheads and hulls apart.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 19-05-2008, 01:12   #24
Senior Cruiser
 
Lancerbye's Avatar

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Ladysmith,BC, Vancouver Island , Canada
Boat: Lancer 44 Motorsailer
Posts: 1,757
Images: 32
When you use basic statistics to validate your policy which insurance companies do, it is easy to see how more cats are prone to lightening strikes, because the larger cat population are more common in the Florida/Carabean area where lightening strikes are more common. In the Pacific Northwest Cats are rare and so are lightening strikes.
__________________
The basis of accomplishment is in never quitting
Mengzi Meng-tse
Lancerbye is offline   Reply With Quote
Old 19-05-2008, 05:42   #25
CF Adviser
Moderator Emeritus
 
Hud3's Avatar

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Virginia
Boat: Island Packet 380, now sold
Posts: 8,929
Images: 49
Quote:
Originally Posted by David M View Post
I would like to see these statistics and not just opinions. Do catamarans actually have more claims than monohulls? Are there any available statistics? This may make or break whether I buy a catamaran or not. Not so much the premiums, but are cats statistically more dangerous?

How on earth a catamaran is more prone to lightning strikes is beyond me. Any ideas?

David
The author of the material that Gord posted is a frequent contributor to the Caribbean Compass, and from my reading of his articles, he appears to be competent and to value accurate data, so I would take his statements at face value, and assume they are based on hard data.

Regarding his statements that catararans have more claims and higher risk of capsize than monohulls, the question to ask is, "Why"? My answer would be that "operator error" probably has a lot to do with it. Sailing a cruising catamaran safely requires some different techniques and skills/experience compared with sailing a monohull. Mishaps will naturally occur as those skills are developed.
__________________
Hud
Hud3 is offline   Reply With Quote
Old 19-05-2008, 21:18   #26
Senior Cruiser
 
Therapy's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: W Florida
Boat: The Jon boat still, plus a 2007 SeaCat.
Posts: 6,894
Images: 4
Quote:
Originally Posted by David M View Post
I would like to see these statistics and not just opinions. Do catamarans actually have more claims than monohulls? Are there any available statistics? This may make or break whether I buy a catamaran or not. Not so much the premiums, but are cats statistically more dangerous?

How on earth a catamaran is more prone to lightning strikes is beyond me. Any ideas?

David
From another thread.....Can't believe you missed it.




These multi/mono threads tend to generate a lot of "heat", but not much "light" (as in "enlightenment").

I recently came across an interesting post in the SSCA forum that describes the author's attempt to analyze actual data from records of boating accidents and insurance company acturial information. The poster, Sandy Daugherty, was an employee of the U.S. National Transportation Safety Board (NTSB). The data were not perfect, but Sandy was able to make some interesting observations and draw a few conclusions.

The entire post is included below, with the kind permission of the author. Thanks, Sandy!

Hud


" Before I retired from the NTSB I had the opportunity to study the complete Coast Guard database of boating accidents and Summary
Data of proprietary actuarial information from sources within the Lloyds' Groups, with a focus on vessels with accomodations including permanent berths, head(s) and galley. I tried to exclude beach cats and tris, and daysailers by excluding boats under 24 feet.

The data was not user-friendly and required a lot of external correlation because many vessels were incorrectly classified. That ultimately prevented releasing any conclusions because GI+MGI=GO (garbage in plus more garbage in still equals garbage out.) This was also a problem with the older NTSB databases that included pre-digital-age reporting. However, I discovered in the process that there were few differences between monohul and multihull rates of occurrence. That's easy to understand; human error trumps mechanical failure and design deficiency evermore.

Here are some of the facts that did become apparent:
Vessels designed for racing and record attempts break. Vessels built for cruising don't break. People who race drive themselves and their vessels to the limit. [please forgive the pun] Cruisers drive their homes to the next nice place.

The rates of actual vessel loss (outside of competition) remained the same for monohulls and multihulls, over many years, with catamarans emerging slightly ahead of other vessels in the last years of available data. Reports of large numbers of catamaran roll-overs are probably anecdotal as accident statistics reveal a (slight) decline, with a slight increase in sinkings among monohulls. There was a lot of confusion in the data between catamarans and trimarans, which I can only suggest an interpretation for:

Vessels purpose built for competition are not recorded as such. Each accident had to be researched individually. Many were not insured, meaning that Insurance data would not take them into account. In fact, Many sinkings of monohulls were extremely difficult to document because they were never widely reported. This is changing as news media is becoming more interested, especially in colorful visuals.

A very small percentage of trimarans are sold for cruising, as a very small percentage of catamarans are sold for racing. The best correlation between racing and competition vessels was a ratio of lwl to mast height.

Where I was able to distinguish between cruising and competition vessels, I found that the rate of personal injuries and single fatalities was higher among monohulls. That should merit further study because those injuries appeared to occur in better weather conditions, not in worse. These accidents included cabin injuries, man-overboards, and deck injuries such as inadvertant jibes.

My conclusions were impaired by the quality of data, and my proposal of a National Transportation Safety Board Special Study was properly overshadowed by more important issues. But there is enough factual data to prove that cruising multihulls are no more, and possible less dangerous than cruising monohulls in all reported conditions of weather, traffic, and human frailty, regardless of location."

__________________
__________________
Therapy is offline   Reply With Quote
Old 19-05-2008, 23:46   #27
Registered User
 
Nauticatarcher's Avatar

Join Date: Jun 2007
Location: Mooloolaba, Qld
Boat: Islander Freeport 36
Posts: 396
"A large conductor over the side of the boat will not completely protect you. A cable the same diameter of the mast might be better"
one of the boats here in Opua uses a length of chain in a plastic pipe to stop it damaging hull, hung over side of boat and clipped to main shrould to minimise lightening strike damage, but I'm of the opinion if you get hit you get hit and nothing is really going to help
__________________
Nauticatarcher is offline   Reply With Quote
Old 20-05-2008, 20:17   #28
Sponsoring Vendor
 
Tellie's Avatar

Community Sponsor

Join Date: Oct 2007
Location: Hollywood, Fl.
Boat: FP Athena 38' Poerava
Posts: 3,046
We used to do commercial electrical repair due to lightining strikes all over S.Fla. The one thing I know for sure, if you plan on providing a path for the static voltage from a direct lighting strike away from anything, much less a boat of any kind, you'll need a conductor the size of a large tree trunk. Aside from a Faraday cage around your boat and a large lightning arrester there's really not much you can do but play the odds that sailors aways have.
Tellie is offline   Reply With Quote
Old 21-07-2008, 01:10   #29
Registered User

Join Date: Jul 2008
Posts: 81
Quote:
Originally Posted by Fishspearit View Post
That's the line that has me scratching my head

Can anyone explain why that would be?
Most of the boats I see are tied up in a marina. if where the lightning strikes in a marina is random, and a catamaran takes up two slips, won't it be twice as likely to get a hit?
__________________
decktapper is offline   Reply With Quote
Old 21-07-2008, 12:01   #30
Kai Nui
Guest

Posts: n/a
I am not an actuarial, but I can see how common misconceptions, and innuendo can make it's way into underwriting decisions.
I believe allot of it has to do with what many accept as common knowledge, and the numbers that are not considered.
Take Ferro boats. Although many were built in the 70's and 80's, few went in the water, and even fewer were insured. If the insurance industry takes figures from their books to determine the risk, the smaller the overall number, the greater impact a single occurrence will have on the statistics.
Consider hull materials. Most wood boats are worked on by the owners. There are limited resources around to do repair on wood boats, because there is less demand, and the skills are highly specialized. This does not make the wood Hull any less sound, but it does affect the repairability of the vessel. Couple this with the replacement cost of a well maintained wood boat, and the risk is very high. Then take the numbers again, and consider the number of insured wood boats out there. In contrast to the number of fiberglass vessels, it is relatively low. Again, each individual incident has a much higher impact on the numbers used to calculate the risk.
The bottom line is that these figures are simply a fact of life we have to deal with. It is a standard that all insurance companies use to set their rates. The only variable we, as a community can have an impact on, is the human factor. The more experienced sailors there are out there, using their boats, as opposed to letting them rot in the marina, the fewer claims for sinking at the dock will be presented.
__________________

__________________
  Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Health Insurance ? irwinsailor Dollars & Cents 148 27-12-2016 19:42
Medical Insurance FreedomSeekers Dollars & Cents 12 09-05-2006 10:25
Insurance for a circumnavigation Gisle Dollars & Cents 3 29-04-2006 11:19
opinions on Irwin orcabait Monohull Sailboats 25 23-08-2004 08:23
Personal effects insurance. tenknots Dollars & Cents 0 16-04-2003 01:18



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 15:18.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.